Improved derrick for raising sunken vessels



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M uw l GRAPHER. WASHINGTON, D C.

UNITED STATES PATENT OFFICE.

SHERMAN PETRIE, OFFBUFFALO, NEW YORK.

IMPROV'ED DERRICK FOR RAISING SUNKEN VESSELS.

Speciiication forming part of Letters Patent No. 57,183, dated August 14, 1866.

To all 'whom it may concern:

Beit known that I, SHERMAN PETRTE, of the city of Buffalo, county of Erie, and State of New York, haveinvented a certain new and Improved Wrecking-Derrick; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, making a part of this specification.

The nature of this invention consists in the combined use of two independent derrick vessels or iioats having each a number of masts, and each mast provided with a double set of lifting tackle and chains, so that, the derrickvessels being arranged one on each side of a s-unken vessel, one set of lifting-chains may be passed in under the same, leading down between the derrick-vessels, and the other set also passed in under but leading down outside of the derrick-vessels, whereby the strain of lifting the sunken vessel is distributed equally between the inside and outside chains in a manner to maintain the derrick-vessels in an upright position and prevent undue listing or careenin g thereof.

In the accompanying drawings, Figure I is cross-sectional elevation of the two derrickvessels, showing their arrangement in relation to a sunken vessel, and also the arrangement of the lifting chains andtackle. Fig. II is a deck plan of a portion of one of the vessels; and Fig. III is a side elevation of one of the derrick-vessels.

Letters of like name and kind refer to like parts in each of the figures.

A A represent the derrick-vessels, of a model and build which will embrace the greatest buoyancy and strength, their size being determined by the labor they are to be required to perform. They are strengthened by a solid longitudinal rib or backbone, A', which will impart great stiffness and rigidity and assist them to bear the severe strains to which they must necessarily be subjected.

B B represent the masts which support the lifting-tackle. These may be three, four, or more in number, and as large and high as the service :may require.

C G represent the lifting-tackle, consisting of strong ropes and blocks, each set of tackle having a stationary block, D, and a movable block, D', the stationary blocks being secured by heavy iron rings to the mastheads, and

the movable blocks connecting with the lifting-chains. Each mast carries a double set of tackle, the one for operatin g the inside liftingchains andthe othe rfor operating the outside lifting-chains.

Each tackle-fall leads through a snatchblock, E, at the foot of its `mast to a windlass or capstan, F, by which it is operated.

G represents the inside lifting-chains, which lead down between the derrick-vessels, and are passed in under the sunken vessel to be raised, as represented in Fig. I. One end of the chains connects with the inside liftingtackle of one derrick-vessel and the other with the inside tackle of the other vessel.

Gr represents the outside lifting-chains', leading down outside of the derrick-vessels, and also passing in under the sunken vessel, with their ends connecting with the outside liftingtackle of the derrick-vessels.

Each lifting chain and tackle is disconnected from the others, and has its own capstan or windlass, so that it may be operated independently of the others. The chains being passed in under the sunken vessel in the mauner described, the operation of the capstans will, through lifting-tackle, lift and raise the saine, the strains on the inside chains, which, unresisted, -would cause the derrick-vessels to careen toward each other, being counterbaL anced by an equal strain on the outside chains and the vessels maintained in their upright position. At the saine time the vessels are sufficiently independent of each other to enable them to rise and fall with the waves without materially ai'ecting their safety or efficiency.

When the sunken vessel has been raised as high as the length or movement of the tackle will permit, and it' becomes necessary to iieet7 or take a new hold on the li'ftingchains, she may be held by one-half of the chains, (which should be strong enough for this purpose,) while the operation of eeting7 is performed with the other half.

The capstans may be operated by hand or by horse or steam power.

The buoyancy of the derrick-vessels, the size and strength of the masts and lifting chains, and the multiplying power of the tackle must be calculated to the service which the apparatus is to perform.

In some instances it may be difficult to pass the lifting-chains in under the sunken vessel. In this case the inside chains may be provided with strongv hooks, which may be caught in the hatchways or other available points.` and the outside chains passed simply in under and across from one derriok-vessel to the other, in Which arrangement they will still have the desired effect of preventing the careening of the derrick vessels; or the inside and outside chains may both be hooked into the hatches or sides or any available points of the sunken vessel.

What I claim as my invention, and desire to secure by Letters Patent, is

The double set of lifting-tackle C C and chains G G', arranged, combined, and operating1 substantially as described, by which a sunken vessel may be raised and at the same time the derrick-vessels maintained in their upright positions, as set forth.

` SHERMAN PETRIE.

Witnesses :v A

TRUMAN C. WHITE, B. H. MUEBLE. 

